In magnetic recording, as one example, reading and writing are performed by one or more heads that move relative to the surface of the storage medium. The head typically flies above the surface, supported by a cushion of air, which is sometimes referred to as an “air bearing.” However, under some circumstances—e.g., when the storage device is dropped while in operation—the head may touch the surface. Such an occurrence may be referred to as “touchdown” or, more colloquially, a “head crash.”
When touchdown occurs, contact between the head and the surface of the storage medium may so damage the head, the surface of the storage medium, or both, so that the storage device can no longer be used, particularly if contact persists for an extended period of time.